Barracks
The citadel has barracks that house the soldiers inside. Aizen went to see it himself with his own eyes. The place was walled and spans towards the side. Making it a huge place with spiked walls. The gate was open and had many spiked fences on the front.
He entered and can only hear the beating of the wind from the walls. He felt sad to look at all bodies that were on the way. His mind was thinking that they died gruesome deaths. Making him sigh as he can't help it.
Having several bodies on the ground made Aizen covered his mouth from the smell of decay. He lit the torches afterwards one by one and entered the gate.
Upon entering, he saw ghouls digging their mouths into the dead bodies littered on the ground.
Eating on the corpses of the necromancers that have fallen from battle. He also saw dead guards being eaten, adding to a brooding atmosphere. The dead bodies were massacred and some were missing some limbs.